This invention relates to fire protection systems, more particularly, to an improved spinkler head for use in automatic sprinkler systems.
Heretofore, various forms of sprinkler heads have been proposed for use in sprinkler systems. Typically, sprinkler heads include a body defining a nozzle and a frame having a pair of arms which extend from the nozzle and which are joined at a frusto-conical portion opposite and coaxially aligned with the nozzle. Some form of distributor plate is usually attached to the frame at the frusto-conical portion to prevent upward spray of the liquid issuing from the nozzle. Examples of such prior sprinkler heads may be found in U.S. Pat. No. 2,664,956, entitled SPRINKLER HEAD, issued on Jan. 5, 1954 to Barz; U.S. Pat. No. 2,697,008, entitled SPRINKLER HEAD, issued on Dec. 14, 1954 to Rowley and U.S. Pat. No. 2,724,614, entitled SPRAY SPRINKLER, issued on Nov. 22, 1955 to Rider.
The sprinkler heads of the type exemplified by these aforementioned prior patents include deflectors and/or distributor plates which are configured and interact to atomize or finely divide the liquid emanating from the sprinkler head. Such atomizing sprinkler heads have been ineffective in controlling fast-burning, high-heat output fires.
A system employing present atomizing sprinkler heads in order to effectively control and extinguish such high-heat output fires, requires a large number of heads installed over the area, an increase in the extent and size of piping, an increase in the sizing of the fire pump as well as the capacity of the pump suction tank. These design requirements are such that the cost of the system may become prohibitive.
Fires of the type under consideration produce a burst of flame generally known as a fire plume. The fire plume or burst of flame may rise as fast as 55 feet per second. The small or finely divided drops of water produced by the standard, atomizing sprinkler heads, as exemplified by the aforementioned patents, are unable to effectively penetrate the fire plume and extinguish the burning material. The violent drafts produced by these fires blow the water sideways and upwards so that effective quantities of water do not reach the seat of the fire. Temperatures at the ceiling of the building increase drastically as the fire intensifies and spreads. The steel or reinforced concrete of the building may be severely damaged. Such high heat output fires produce 250,000 BTU per minute or more. It should therefore be apparent that conventional sprinkler designs and layouts are unable to control let alone extinguish such high-heat output fires.
A need exists for an improved, sprinkler head having increased fire extinguishing effectiveness for a given water supply, which is capable of controlling and extinguishing high-heat output fires such as those associated with stacked plastic material, which results in a reduction in installation costs for systems protecting such areas by reducing pipe size requirements and/or permitting wider sprinkler spacing and lower water capacities and which may be used as a replacement in existing sprinkler systems.